From 5d1e21d28a93415b66401d27a30ee8eb6b2b66a8 Mon Sep 17 00:00:00 2001
From: Nicholas Noll <nnoll523@gmail.com>
Date: Fri, 29 Oct 2021 16:21:35 -0700
Subject: checkin

---
 sys/cmd/rc/input.c | 68 +++++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 47 insertions(+), 21 deletions(-)

(limited to 'sys/cmd/rc/input.c')

diff --git a/sys/cmd/rc/input.c b/sys/cmd/rc/input.c
index 8ca3145..08363f0 100644
--- a/sys/cmd/rc/input.c
+++ b/sys/cmd/rc/input.c
@@ -133,7 +133,7 @@ insertcursor(int fd)
     write(fd,"\e[6 q",5);
 }
 
-/* Raw mode: 1960 magic shit. */
+/* raw mode: 1960 magic shit. */
 static
 int
 enterraw(int fd) 
@@ -143,7 +143,7 @@ enterraw(int fd)
     if(!shell.interactive)
         goto fatal;
 
-    if(!mode.defer) {
+    if(!mode.defer){
         atexit(doatexit);
         mode.defer = 1;
     }
@@ -167,7 +167,9 @@ enterraw(int fd)
     raw.c_cc[VMIN] = 1; raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
 
     /* put terminal in raw mode after flushing */
-    if (tcsetattr(fd,TCSAFLUSH,&raw) < 0) goto fatal;
+    if(tcsetattr(fd,TCSAFLUSH,&raw) < 0)
+        goto fatal;
+
     mode.raw = 1;
     return 1;
 
@@ -180,13 +182,13 @@ static
 void
 exitraw(int fd)
 {
-    /* Don't even check the return value as it's too late. */
+    /* don't even check the return value as it's too late. */
     if(mode.raw && tcsetattr(fd,TCSAFLUSH,&originalterm) != -1)
         mode.raw = 0;
 }
 
-/* Use the ESC [6n escape sequence to query the horizontal cursor position
- * and return it. On error -1 is returned, on success the position of the
+/* use the esc [6n escape sequence to query the horizontal cursor position
+ * and return it. on error -1 is returned, on success the position of the
  * cursor. */
 static
 int
@@ -325,7 +327,7 @@ refreshsingleline(struct TerminalState *term)
     char esc[64];
     struct Buffer ab;
 
-    int    n;
+    int    n, w;
     rune   r;
     int    fd    = term->ofd;
     intptr off   = term->prompt.size;
@@ -334,13 +336,12 @@ refreshsingleline(struct TerminalState *term)
     intptr pos   = term->cursor.pos;
     intptr col   = term->cursor.len;
 
-    assert(col);
-    assert(off);
-
     while((off+pos) >= term->cursor.cap){
         n = utf8·decode(buf, &r);
+        w = utf8·runewidth(r);
+
         buf+=n, len-=n;
-        pos--,  col--;
+        pos-=w,  col-=w;
     }
 
     assert(buf <= term->edit.buf + len);
@@ -481,19 +482,18 @@ refreshline(struct TerminalState *term)
 int
 insertrune(struct TerminalState *term, int n, char *c)
 {
+    int  w;
     rune r;
 
+    utf8·decode(c, &r);
+    w = utf8·runewidth(r);
+
     if(term->edit.len + n <= term->edit.cap){
         if(term->edit.pos == term->edit.len){
             memcpy(term->edit.buf+term->edit.pos, c, n);
 
-            term->edit.pos+=n,  term->edit.len+=n;
-            term->cursor.pos++, term->cursor.len++;
-
-            utf8·decode(c, &r);
-            if(wcwidth(r) < 1){
-                exit(1);
-            }
+            term->edit.pos   += n, term->edit.len   += n;
+            term->cursor.pos += w, term->cursor.len += w;
 
             term->edit.buf[term->edit.len] = '\0';
 
@@ -968,6 +968,33 @@ action:
 
 #define END(term)  (Position){(term).edit.len, (term).cursor.len}
 
+static
+int
+size(char *s)
+{
+    rune c;
+    int  n, len = 0;;
+    while((c=*s)){
+        if(c == '\033'){
+            n = 1;
+        esccode:
+            c = s[n];
+            if(!c) // we hit end of string in the middle of parsing an escape code!
+                return len;
+            if(c == 'm'){
+                s += n + 1;
+                continue; // outer loop
+            }
+            n++;
+            goto esccode;
+        }
+        n = utf8·decode(s, &c);
+        s   += n;
+        len += utf8·runewidth(c);
+    }
+    return len;
+}
+
 /* this function is the core of the line editing capability of linenoise.
  * it expects 'fd' to be already in "raw mode" so that every key pressed
  * will be returned asap to read().
@@ -1000,7 +1027,7 @@ interact(int ifd, int ofd, char *buf, intptr len, char *prompt)
 
     term.prompt.s      = prompt;
     term.prompt.len    = strlen(prompt);
-    term.prompt.size   = utf8·len(prompt);
+    term.prompt.size   = size(prompt);
 
     term.cursor.pos    = 0;
     term.cursor.len    = 0;
@@ -1271,8 +1298,7 @@ printkeycode(void)
 }
 
 /*
- * This function calls the line editing function edit() using
- * the stdin set in raw mode
+ * this function calls the line editing function edit() using the stdin set in raw mode
  */
 static
 int
-- 
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